Distributed Detection of Multi-Hop Information Flows With Fusion Capacity Constraints

The problem of detecting multihop information flows subject to communication constraints is considered. In a distributed detection scheme, eavesdroppers are deployed near nodes in a network, each able to measure the transmission timestamps of a single node. The eavesdroppers must then compress the information and transmit it to a fusion center, which then decides whether a sequence of monitored nodes are transmitting an information flow. A performance measure is defined based on the maximum fraction of chaff packets under which flows are still detectable. The performance of a detector becomes a function of the communication constraints and the number of nodes in the sequence. Achievability results are obtained by designing a practical distributed detection scheme, including a new flow finding algorithm that has vanishing error probabilities for a limited fraction of chaff packets. Converse results are obtained by characterizing the fraction of chaff packets sufficient for an information flow to mimic the distributions of independent traffic under the proposed compression scheme.National Science Foundation (U.S.) (Grant No. CCF-0635070)United States. Office of Naval Research (MURI W911NF-08-1-0238

Distributed recovery of a Gaussian source in interference with successive lattice processing

A scheme for recovery of a signal by distributed listeners in the presence of Gaussian interference is constructed by exhausting an "iterative power reduction" property. An upper bound for the scheme's achieved mean-squared-error distortion is derived. The strategy exposes a parameter search problem, which, when solved, causes the scheme to outperform others of its kind. Performance of a blocklength-one scheme is simulated and is seen to improve over plain source coding without compression in the presence of many interferers, and experiences less outages over ensembles of channels. Keywords: network information theory; distributed source coding; lattice code